Premium
A folded and functional protein domain in an amyloid‐like fibril
Author(s) -
Sackewitz Mirko,
von Einem Sabrina,
Hause Gerd,
Wunderlich Michael,
Schmid FranzXaver,
Schwarz Elisabeth
Publication year - 2008
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.073276308
Subject(s) - fibril , biophysics , cold shock domain , chemistry , protein domain , protein structure , protein folding , alanine , fusion protein , amyloid (mycology) , crystallography , biochemistry , amino acid , biology , recombinant dna , rna , gene , inorganic chemistry
The effect of the polypeptide environment on polyalanine‐induced fibril formation was investigated with amyloidogenic fragments from PAPBN1, a nuclear protein controlling polyadenylation. Mutation‐caused extensions of the natural 10 alanine sequence up to maximally 17 alanines result in fibril formation of PABPN1 and the development of the disease oculopharyngeal muscular dystrophy (OPMD). We explored the influence of fibril formation on the structure and function of a one‐domain protein linked to the fibril‐forming part of PABPN1. The well‐characterized, stably folded, one‐domain protein, cold‐shock protein CspB from Bacillus subtilis , was fused either to the C terminus of the entire N‐terminal domain of PABPN1 or directly to peptides consisting of 10 or 17 alanine residues. The fusion protein between the N‐terminal domain of PABPN1 and CspB formed fibrils in which the structure and activity of CspB were retained. In the fibrils formed by fusions in which the polyalanine sequence was directly linked to CspB, CspB was unfolded. These results indicate that the folded conformation and the function of a protein domain can be maintained in amyloid‐like fibrils, and that the distance between this domain and the fibril plays an important role.